Title: Validation of an LDH assay for assessing nanoparticle toxicity.

Authors: Han, Xianglu; Gelein, Robert; Corson, Nancy; Wade-Mercer, Pamela; Jiang, Jingkun; Biswas, Pratim; Finkelstein, Jacob N; Elder, Alison; Oberdorster, Gunter

Published In Toxicology, (2011 Sep 5)

Abstract: Studies showed that certain cytotoxicity assays were not suitable for assessing nanoparticle (NP) toxicity. We evaluated a lactate dehydrogenase (LDH) assay for assessing copper (Cu-40, 40nm), silver (Ag-35, 35nm; Ag-40, 40nm), and titanium dioxide (TiO(2)-25, 25nm) NPs by examining their potential to inactivate LDH and interference with ýý-nicotinamide adenine dinucleotide (NADH), a substrate for the assay. We also performed a dissolution assay for some of the NPs. We found that the copper NPs, because of their high dissolution rate, could interfere with the LDH assay by inactivating LDH. Ag-35 could also inactivate LDH probably because of the carbon matrix used to cage the particles during synthesis. TiO(2)-25 NPs were found to adsorb LDH molecules. In conclusion, NP interference with the LDH assay depends on the type of NPs and the suitability of the assay for assessing NP toxicity should be examined case by case.

PubMed ID: 21722700

MeSH Terms: Animals; Cells, Cultured; Copper/toxicity; Dose-Response Relationship, Drug; L-Lactate Dehydrogenase/metabolism*; Male; NAD/metabolism; Nanoparticles/toxicity*; Particle Size; Rats; Silver/toxicity; Titanium/toxicity